Add a way to re-enable hardware acceleration on Linux

[TheFeelTrain]

Is your feature request related to a problem? Please describe.
With the latest update hardware acceleration is forced off which results in the UI being extremely laggy while using a custom theme. I never had the black screen bug this was intended to fix.

Describe the solution you'd like
A launch option or setting to re-enable acceleration. The way it's been implemented the only way to enable it is to edit main.cpp and recompile it without the hard-coded --disable-gpu flag.

[RPDJF]

why was it disabled in the first place ?

EDIT: never mind, found it in there: c1cae32

why did they released it ? it's barely usable without gpu accel

[RPDJF]

i wonder if the blackscreen issue came at some point
i didn't had this issue 2 weeks ago, but now, when recompiling the mediaplayer without the flag, I indeed get a blackscreen due to gpu accel

[169188:169260:0330/134036.280556:ERROR:gpu_channel.cc(449)] GpuChannel: Failed to create SharedImageStub
[169188:169260:0330/134036.281236:ERROR:gl_context_egl.cc(259)] eglCreateContext failed with error EGL_BAD_CONTEXT
[169188:169260:0330/134036.281245:ERROR:gpu_channel_manager.cc(753)] ContextResult::kFatalFailure: Failed to create shared context for virtualization.```

[SunRed]

I noticed the UI being weirdly laggy lately and came here to confirm my suspicion as the inclusion of the flag to disable hw acceleration went past me when I upgraded the client.

Recompiling the client without the flag being set, I can't reproduce the blackscreen issue people have been reporting. Hardware acceleration just works as expected.
This is on an up-to-date Arch Linux system with Plasma 6.3 on Wayland and Mesa 25.0.2 using an amd gpu.

Looking at the issues linked in c1cae32 it seems only to affect nvidia users using the proprietary drivers.
Removing the hardcoded flag again and using an environment variable to disable hw acceleration/setting the flag for those with problems (e.g. QTWEBENGINE_CHROMIUM_FLAGS="--disable-gpu" works) would be the sensible choice imo as it doesn't seem to affect the majority of users.

[mihawk90]

Agree it's not really ideal to impose hardcoded sub-par performance on every user just because some users might be affected, especially when the cause isn't even known (except for Nvidia doing Nvidia things).

I think the alternate workaround of forcing to run under XWayland would have been better in this case.

It is also not ideal, but better for the overall userbase then just disabling GPU rendering entirely.